1. Field of the Invention
The present invention relates to a fiber glass mainly composed of calcium phosphate, and particularly to a fiber glass for filling in a defect or hollow portion of bone and including calcium phosphate as a main ingredient.
2. Prior Art
In the surgical and orthopedic treatments, prosthesis operations are often required for filling in defects or hollow portions of bone resulting from fracture of bone or surgical removal of bone tumor. Also in the field of dental surgery, similar denture operations are often required for filling in spoilt void portions in maxilla or mandibula resulting from pyorrhea alveolaris. It has been a common practice to resect ilium from the patient to fill up the defect or hollow portion of bone thereby to promote early remedy of the bone tissue. However, by means of such an operaton, normal bone tissue must be picked up from an unspoilt portion which causes additional pain to the patient, and, in addition the operation is very troublesome. Moreover, when the volume of defect or void in the patient's bone is large, the amount of bone obtainable from his own body is not always sufficient for fully filling in the defect or void. In such a case, it is inevitable to use a substitute for the patient's own bone tissue. Although the same or different sorts of bone tissue have been used as the substitute, there remains the problem that the implanted substitute is rejected by the living tissue due to foreign body rejection reaction. For these reasons, the post-operation recovery of the defect is not always satisfactory. Accordingly, such an operation has not yet been recognized as fully satisfactory in practice.
There is, therefore, a demand for an artificial material which is excellent in compatibility with living tissues when filled in a defect or hollow portion of bone to facilitate formation of bone within and at the vicinity of the defect and to promote repair and recovery of the structure and function of the once damaged bone tissue.
A variety of metal alloys and organic materials have hitherto been used as the substitute for the hard tissues in the living body. However, it has been recognized that these materials have the tend to dissolve or otherwise deteriorate in the environment of living tissue or to be toxic to the living body, and that they cause a so-called foreign body reaction. Ceramic materials are used up to date, since they are excellent in compatibility with living body and are free of the aforementioned difficulties. From ceramic materials, particularly alumina, carbon or tricalcium phosphate or a sintered mass or single crystal of hydroxyapatite, which are superior in compatibility with living body artifical bones and teeth have been developed and have attracted a good deal of public attention.
However, the conventional ceramic implant materials have a common disadvantage in that they are inherently too hard and brittle. Therefore, these known ceramic materials are not fully satisfactory in practical use. It has also been attempted to fill in a defect of bone with a sintered ceramic block or a ceramic block of single crystal form. However, since uneven gaps or interstices are formed between the block and the bone tissue, the object of fully filling in the void in the bone cannot be attained. On the other hand, when alumina is used as the filler, it acts as a stimulant to cause absorption of bone at the vicinity of the implanted filler, since alumina is much harder than the bone tissue. The use of ceramic materials has not yet been in the stage of practical application, accordingly. Furthermore, it has not been clarified what properties the ceramic material should have to suppress the foreign body reaction, to improve the compatibility with living body and to promote formation of new bone.